There are a number of settings and applications where a purified fluid is needed. This includes, but is not limited to, sterile fluid for infusion, consumption, and/or bathing of patients with compromised immune systems, and further, other laboratory or industrial applications or uses where purified (sterilized) fluid is required. In a number of applications, tap water from a municipality can not be used even for bathing of a patient that may have a suppressed or weakened immune system or has some other condition where particulate and other foreign matter, including bacteria, contained in the tap water can jeopardize the health of the patient.
For example, there have been a number of recent outbreaks of Legionanaires' disease that have been linked to an infected water supply and the patient coming into contact with this supply. Legionellosis is an infection caused by the genus of Gram negative bacteria Legionella, notably, L. pneumophila. L. pneumophila is an ubiquitous aquatic organism that thrives in warm environments and typically accounts for over 90% of Legionnaires disease. Legionellosis infection occurs after persons have breathed mists that come from a water source (e.g., air conditioning cooling towers, whirlpool spas, and showers) contaminated with Legionella bacteria. Persons may be exposed to these mists in hotels, workplaces, hospitals or public places. Legionella organisms can be found in many types of water systems. The bacteria will grow in water temperatures from 68° F. to 124° F. However, the bacteria reproduce at the greatest rate in warm, stagnant water, such as that found in certain plumbing systems and hot water tanks, cooling towers and evaporative condensers of large air-conditioning systems and whirlpool spas.
This is merely one example of a type of bacteria that can be present in water and cause health problems and in some cases be fatal when consumed or when the patient comes into contact with infected potable water. Other types of bacteria can cause stomach aliments when consumed or other undesired health issues.
In order to ensure a clean, healthy supply of water, a filter device or the like is often used to clean unwanted foreign matter from the water. Such a device will often have a filter membrane or the like that filters the water supply. In some settings where it is critical to have a sterile supply of water or the like, a redundant filtration system is provided to ensure the necessary level of safety. These types of systems include not only a first filtration stage but also a second filtration stage that acts as a redundant filtration stage since it receives filtered water from the first stage and then performs a second filtration operation on the filtered water to ensure that water discharged from the device is purified and suitable for use.
It will also be appreciated by those skilled in the art that liquid (water) treatment facilities are needed in various fields which require treatment of water on site, such as at an industrial plant or the like, as well as in-field uses where it is desirable for the water to be treated at a remote location, such as during a camping trip or at a remote military location etc., where it is difficult or impossible to contain and supply potable water. For example, when camping or hiking, it is very cumbersome to carry the necessary water supply due to the sheer weight of the water itself. This makes it difficult since it is an absolute requirement for an individual to consume the necessary amounts of water to replenish fluid in the body and remain properly hydrated.
Unfortunately, access to a potable water supply may be difficult, if not impossible, depending upon the circumstances and the precise location. In addition, in locations that are either remote and/or dangerous, such as a military operation, it may be difficult for a person to have the time or ability to purify a water supply. For example, when camping or when otherwise being in a natural setting, it may be unsafe to drink running water from rivers, streams, lakes, etc., since these sources may contain foreign matter, such as microorganisms, organic wastes, etc., that can at the very least lead to sickness and discomfort and at worst, can even lead to serious health concerns and even death in the most extreme situations, as when harmful chemicals or poisonous natural elements are consumed.
There are a number of governmental bodies and agencies that undertake regulating the public drinking water supply. In particular, the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) assure the safety and health of the public by setting and enforcing standards both outside and inside the workplace. There are a number of regulations to govern the standards that apply to water consumption and especially, public water systems. The standards protect public health by limiting the levels of contaminants in drinking water, with some common contaminants being microorganisms, organic matter, inorganic and organic chemicals, disinfection by-products, disinfectants, etc.
However and as previously mentioned, it is difficult to carry and/or generate a sufficient supply of drinking water when an individual is located in a remote location, such as the wilderness, even when there is abundant water around since the water may not be potable. While there has been work done in the field of portable water treatment facilities, these facilities and systems tend to be either too complex, cumbersome and generally impractical since they most often are not that portable in design.
Moreover, there is a need for a simple single cartridge design that can be used in remote or stationary applications and is constructed to provide redundant filtration within the single cartridge body or casing.